On Jan 3, 4:02*pm, DD_BobK wrote:
On Jan 3, 1:00*pm, " wrote:

http://www.ehow.com/how_4669902_sola...html?ref=fuel&....

Copper rolls come in 60' rolls *which makes it easy and compact to
build a Solar Collector around. * I reckon one roll would provide
enough hot water for a 40 gallon water heater in FLorida...but another
roll could always be implemented easy enough. *Price on a roll of 3/4"
copper runs about $140 with maybe another $50 in misc. collector box
materials, making it awefully inexpensive . *A suitable heavy duty
water pump runs about $140 ,

What do u think ? *Have you got a solar collector ? * Please share.
Thanks.

About 45 years ago (mid 60's) *my dad & I built a "solar pool heater"
out of 20' sticks of 1/2" (nomimal; 5/8" OD) copper tubing.
We used U-fittings ....lots of soldering. *And we placed the tubing
assembly, *two or three layers to minimizing "self shade", in "box"
with glass cover.

It worked ok but the box foggedd up with condensation & we abandoned
the concept......

A number of year later (after a re-roof) I convinced him to forget the
box and just place old tubing in a single layer on the shake roof.

In the early 70's when solar collection became quite the rage....an
engineering prof asked me to collect data on the system
input water temp
output water temp
sort description of "weather"

My dad was working the swing shift at that time and was more than
happy to take data for us a couple times per day.

The house (& pool) were ideally suited to solar collection....back
yard, pool & main roof (single story ranch) *all ran east & west. The
roof angle was just about optimum for summer time heating. * *House
location was Orange County, CA.

For summer only heating, use latitude minus 10-15. For winter only heating, use latitude plus 10-15. For year around heating, install the collectors at latitude. Variations from these ideals can be compensated for by adding additional collector area.

fromhttp://www.swimmingpool.info/solar-pool-heater.html

On sunny days between 10AM & 2PM *we used to get a pretty decent
temperature rise....like "burn your hand hot" , but the flow rate was
kinda wimpy.

The real "take away" info here is, based on the temperature rise and
the flow rate (pretty much fixed), that the "heater" collected 10 BTU/
hr per foot of copper tube on days with decent sun.

We figured *that our home made heater (about 500 ft) added a few weeks
to the swimming season on each end.....occasionally in summer we had
to disable the heater......pool got too hot (+80F) to be
refreshing.

Oh......... the pool as a bit on the large size....20' x 40' (not an
oval, not a rectangle, more like a rectangle with asymmetric full
radii on each end) and held about 40,0000 gallons

The pool itself was a decent collector itself becuase of exposure and
when my dad finally got a cover for the pool ("bubble wrap" type) the
pool was usable for a much longer season.....but since it was a
"retrofit" cover and no place for a cover real, it was a PITA to
remove & replace.

Copper is a bit spendy but will last forever if oyu keep your water
chem under control. *Plastic is a lot cheaper, shorter life and
probably has reduced collection performance. *If oyu have tons of
space...I'd go with plastic. * If oyu design either system to be
modular you can add units as time & $'s permit.

HTH

cheers
Bob

Thanks everyone for responding. Bob....what do u figure the required
GPM is thru a copper roll collector ? Is it better to really have the
water moving thru it, or, slow it down for greater heat pickup ? Ill
be using the copper roll collector in conjunction with a regular 40
gallon electric water heater for Mobile Homes which have the
accessory top hot/cold ports plugged and ready for piping from a solar
collector. Im pretty excited about building the collector and
installing everything....as I think it will satisfy 100 percent of my
domestic hot water needs since i live alone. I dont know if to use
1/2" od copper roll or 3/4" od (???)